The Subjective Postural Vertical Determined in Patients with Pusher Behavior During Standing

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Human Physiology

Background:

• Pusher behavior, a condition often seen in stroke patients, involves a disturbed sense of subjective postural vertical (SPV).
• Previous SPV measurements in sitting patients yielded contradictory results regarding deviation direction.
• Investigating SPV in standing patients with varying pusher behavior severity is crucial.

Purpose of the Study:

• To investigate the subjective postural vertical (SPV) in standing patients with different degrees of pusher behavior severity.
• To compare SPV in patients with pusher behavior, stroke patients without pusher behavior, and healthy controls.

Main Methods:

• Assessed SPV error and range in pitch and roll planes for three groups: stroke patients with pusher behavior (n=8), stroke patients without pusher behavior (n=10), and healthy controls (n=10).
• Classified pusher behavior severity using the Burke Lateropulsion Scale (BLS).

Main Results:

• In the pitch plane, SPV range was significantly larger in pusher patients.
• In the roll plane, pusher patients showed significantly larger SPV error and range, with an ipsilesional tilt correlated with BLS score.
• SPV error was similar across groups in the pitch plane, but significantly altered in the roll plane for pusher patients.

Conclusions:

• Patients with pusher behavior demonstrate an ipsilesional SPV tilt that diminishes with reduced behavior severity.
• The study highlights a general disturbance in verticality perception sensitivity in these patients.
• Findings underscore the need for rehabilitation strategies to recalibrate the internal model of verticality.